Execute Remote Commands (Command Line & PowerShell)

Hello -

I am unclear on how to run commands on remote machines. Anytime I attempt to run a command be it from the command line or PowerShell, it just opens a command prompt on my local machine.

What steps do I need to follow to A.) run a command-line command on a remote computer and B.) run a PowerShell script on a remote machine

The current documentation isn't very clear to me I'm afraid.

Thank you!